Annette’s Cowry Shell, Pseudozonaria annettae

Annette’s Cowry Shell, Pseudozonaria annettae. Shell collected off the beach in the greater Bahía de los Ángeles area, Baja California, April 2014. Size: 4.8 cm (1.9 inches) x 2.7 cm (1.1 inches). Collection, photograph and identification courtesy of Bob Hillis, Ivins, Utah.

Phylogeny: Annette’s Cowry, Pseudozonaria annettae (Dall, 1909), is a gastropod mollusk that is a member of the Cypraeidae Family of Cowries.  The genus Pseudozonaria is one of fifty-seven genera in this family, and there are five species in this genus. Annette’s Cowry is known in Mexico as Ciprea Annette. Annette’s Cowry was first described by the American naturalist and malacologist William Healy Dall. Dall described over five thousand and four hundred species in his lifetime and thirteen species have been named in his honor. He named this shell, Annette’s Cowry, after his wife, Annette Whitney, whom he married in 1880.

Description: Annette’s Cowry shell is pear-shaped in outline. They lack an operculum and a periostracum They have a whitish or cream colored dorsal surface, which is heavily spotted with brown or chestnut. Ventrally they are pinkish-brown, transitioning to black spots along the sides. Annette’s Cowry shells reach a maximum of 5.5 cm (2.2 inches) in length and 3.0 cm (1.2 inches) in height.

Habitat and Distribution: Annette’s Cowries are found in boulder and reef environments. They live in the intertidal zone and to depths up to 11 m (35 feet). They are tropical Eastern Pacific species. In Mexican waters they are found throughout the entire Gulf of California and along the west coast of mainland Mexico, extending as far south as Guatemala. They have not been reported along the Pacific Coast of the Baja Peninsula.

Ecology and Behavior: Annette’s Cowries are nocturnal, omnivorous, grazers. They are gonochoric and reproduce sexually, with internal fertilization. The eggs are laid in protective capsules. There is no mention in the available literature of them engaging in any types of parasitic, commensal, or symbiotic relationships. From a conservation perspective they have not been formally evaluated however they are fairly common with a relatively wide distribution and should be consider to be of Least Concern.

Synonyms: Cypraea annettae, Cypraea annettae annettae, Cypraea ferruginosa, Cypraea sowerbyi, Pseudozonaria annettae annettae, and Zonaria (Zonaria) annettae.